The present invention generally relates to strengthened, antimicrobial articles with functional coatings and methods for making them for various applications including, but not limited to, touch screens for various electronic devices, e.g., mobile phones, laptop computers, book readers, hand-held video gaming systems, and automated teller machines.
Ion-exchange processes can be used to impart both antimicrobial and strength-enhancing properties in a glass, glass-ceramic or ceramic article by injecting certain metal ions. Antimicrobial properties, for example, can be developed by injecting Ag+ ions into a surface region of the article. The Ag+ ions in the surface region of the article interact with microbes at the surface of the article to kill them or otherwise inhibit their growth. However, the presence and development of these Ag+ ions in the surface region of the article can alter the optical clarity, coloration and/or significantly increase the manufacturing costs of the article.
Accordingly, there is a need for new processes, and particular article configurations, for making strengthened, antimicrobial article products that maximize optical clarity, coloration stability and/or antimicrobial efficacy in a cost effective manner.